Title:
Modelling and Perspectives of Two-stage Pressurized Fermentation
Author(s):
Wonneberger, A.-M., Graf, F., Lemmer, A., Chen, Y., Reimert, R.
Document(s):
Paper
Abstract:
The German government aims for substituting 10·109 m3/a natural gas by upgraded biogas, also called synthetic natural gas (SNG) until 2030. Currently about 0.8·109 m3/a SNG are produced by 146 biogas plants and fed into the German gas grid [1]. A more efficient production of upgraded biogas could help to increase this number and achieve the initial aim. Two-stage pressurized fermentation promises to increase the efficiency of both the production of biogas and its upgrading. In order to evaluate the advantages of pressure and of the two-stage design on the process performance and especially on product gas composition, a process model was developed and validated. Experimentally it was shown that by increasing the pressure the methane content is significantly increased from already about 67 mol-% for the atmospheric operated two-stage fermentation up to 76 mol-% at 9 bar. The model calculations reproduced the findings and additionally reveal potential for even higher methane content in the gas by recycling decompressed liquid and/or by proper pH adjustment, both being currently investigated experimentally. Considering the power demand shows the constraints of such measures and can furthermore be used as a tool for process optimization.
Keywords:
biogas, efficiency, upgrading, synthetic natural gas (SNG)
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Anaerobic digestion for biogas production
Event:
22nd European Biomass Conference and Exhibition
Session:
2CO.13.5
Pages:
539 - 546
ISBN:
978-88-89407-52-3
Paper DOI:
10.5071/22ndEUBCE2014-2CO.13.5
Price:
FREE
